As the name would suggest, they add various useful effects and can be utilized by using innately imbued weapons, such as the Iaito; attained by Weapon Modification; or applied directly to weapons through Resins.
“Divine, also known as Holy, is an Auxiliary Effect in Dark Souls. Divine is an effect possessed...Divine (auxiliary effect)
“Occult, also known as Unholy, is an auxiliary effect in Dark Souls. Occult is an effect...Occult (auxiliary effect)
“Item Discovery is a game mechanic in Dark Souls. Increasing Item Discovery improves the chance...Item Discovery
“Curse is an Auxiliary Effect in Dark Souls. Curse is a hidden effect that is innately imbued on...Curse (Auxiliary Effect)
“Demon is an Auxiliary Effect in Dark Souls. Demon is a hidden effect unique to the weapons...Demon (auxiliary effect)